It has long been customary in containers, such as cigarette packages, to include metal foil material for interior encasement of articles. This material itself has given rise to systems for quality control of packaging, functioning for cigarette packaging to assess whether the parent container for cartons has its required number of individual cartons, whether each carton has its full complement of individual packs and whether each individual pack has its metal foil interior layer.
There has recently been developed a substitute for the conventional metal foil for packaging use, differing primarily from the metal foil in thickness, the substitute being comprised of a carrier or substrate, such as paper, on which is deposited an extremely thin layer of metal, such as aluminum, having thickness approximately one seven hundredth of that of the metal foil. While the customary sheet material has long been detected by radio-frequency field-generating detectors, the substitute material has avoided sensing by such conventional r-f detectors by reason of its reduced thickness. Absent viable detection method and system for the newer packaging material, its benefits of lessened weight and reduced cost remain unavailable to the packaging industry.